National Performance Framework - Clean Seas Indicator 2015
The Clean Seas Indicator for 2015 is 90%. This means that 90% of assessments of metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in biota and sediment in Scottish marine waters show concentrations that are unlikely to harm marine organisms. This is the first time the Indicator has been calculated.
The Indicator is calculated by assessing the concentrations of cadmium, lead, mercury, PAHs and PCBs in biota and sediment in three1 regions: the Northern North Sea, Minches and Western Scotland and Irish Sea (Clyde & Solway). Of the 30 possible assessments, 27 (90%) show acceptable concentrations and 3 show unacceptable concentrations. These are tabulated below with a ✓ indicating acceptable and a ✕ indicating unacceptable.
| compartment | region | cadmium | lead | mercury | PAHs | PCBs |
|---|---|---|---|---|---|---|
| biota | Northern North Sea | ✓ | ✓ | ✓ | ✓ | ✓ |
| biota | Minches and Western Scotland | ✓ | ✓ | ✓ | ✓ | ✓ |
| biota | Irish Sea (Clyde & Solway) | ✓ | ✓ | ✓ | ✓ | ✓ |
| sediment | Northern North Sea | ✓ | ✓ | ✓ | ✓ | ✓ |
| sediment | Minches and Western Scotland | ✓ | ✕ | ✓ | ✓ | ✓ |
| sediment | Irish Sea (Clyde & Solway) | ✓ | ✕ | ✕ | ✓ | ✓ |
The thresholds used to assess whether levels are acceptable differ between contaminants and biota / sediment. Environmental Assessment Criteria (EAC) are used for PCBs in biota and sediment and for PAHs in biota; Effects Range Low (ERL) are used for metals and PAHs in sediment; and European Commission food standards (EC) are used for metals in biota. More information can be found here for biota and sediment.
The raw data used in the assessments can be downloaded here.
Full details of the assessments are available as follows:
These describe the statistical methodology used, and present regional assessments of trends, status with respect to the EAC, ERL or EC, and status with respect to the Background Assessment Concentration, a more stringent threshold used to assess whether concentrations are at background levels.